EUV Radiation Source Fuel Trajectory Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithographic apparatuses using extreme ultraviolet (EUV) radiation sources face challenges in maintaining accurate fuel droplet trajectories due to contamination and thermal drift, leading to inefficient radiation generation and potential nozzle clogging, which affects the precision and stability of the radiation source.
Innovation Solution
A radiation source with a positive lens arrangement utilizing electric and/or magnetic fields to focus and correct the spread of fuel trajectories, ensuring that changes in nozzle position or orientation are minimized, thereby maintaining accurate trajectory alignment and preventing nozzle clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nozzle directs fuel droplets toward a plasma formation location, then radiation generation is enabled, but contamination and thermal drift cause trajectory deviations leading to reduced precision and potential clogging
Solution Approach 1:
A feedback control system continuously monitors the actual trajectory of fuel droplets and adjusts control parameters (such as nozzle positioning or electromagnetic field strengths) to correct deviations caused by contamination or thermal drift, ensuring consistent delivery of droplets to the plasma formation location
Solution Approach 2:
The patent replaces purely mechanical nozzle positioning systems with electromagnetic field-based control mechanisms that can dynamically adjust droplet trajectories without physical contact, reducing wear and improving precision while eliminating mechanical drift issues
2Illumination intensity
If fuel droplets are directed with high accuracy to ensure laser contact, then radiation intensity is maintained, but any obstruction or restriction in the nozzle prevents achieving the desired trajectory
Solution Approach 1:
The patent modifies operational parameters such as fuel viscosity, droplet size distribution, or flow rate to optimize trajectory control while preventing contamination buildup, allowing the system to maintain radiation intensity without requiring perfect nozzle clearance
Solution Approach 2:
The system performs preliminary cleaning or conditioning of the fuel stream before it enters the nozzle, or applies protective coatings to internal nozzle surfaces in advance, preventing contamination from adhering and blocking the flow path that would otherwise compromise trajectory accuracy
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively corrects for both rapid and slow changes in fuel droplet trajectories, enhancing the stability and precision of EUV radiation generation, reducing the need for complex feedback systems and minimizing maintenance requirements.
Implementation Method 1
the lens comprising an electric field generating element and/or a magnetic field generating element
Implementation Method 2
the lens comprising an electric field generating element and/or a magnetic field generating element
Implementation Method 3
a laser configured to direct laser radiation at the stream at the plasma formation location to generate, in use, a radiation generating plasma
Implementation Method 4
The plasma may be created, for example, by directing a laser beam at a fuel, such as particles (i.e., droplets) of a suitable fuel material
Data Source
AI summary
A radiation source comprises a reservoir, a nozzle, a laser, and a positive lens. The reservoir is configured to retain a volume of fuel. The nozzle, in fluid connection with the reservoir, is configured to direct a stream of fuel along a trajectory towards a plasma formation location. The laser configured to direct laser radiation at the stream at the plasma formation location to generate, in use, a radiation generating plasma. The positive lens arrangement configured to focus an at least potential spread of trajectories of the stream of fuel toward the plasma formation location, the lens comprising an electric field generating element and/or a magnetic field generating element.